pianobabe56: what was hardest for me when I was learning this piece was learning how to practice certain parts, like the second half of the Friska with the triple C#s, slowly at first, then building up speed. Unless you are already very good, you can't play it or practice it at speed at first. Be very diligent with the left hand when learning this one. I guess that's true for any piece, but for me the left hand on this one was more difficult than most to get exactly right.
Radix: my hands don't really get tired playing any piece once or twice. Unless you mean mentally exhausting. But even when I am tired once I get into this one I get re-energized. Sorry to all those who have this one high on their list of over-played pieces, but I never get tired of it.